PvRALP1-specific IgG subclass levels and percentages in immune mouse sera. (A) IgG1 (black), IgG2a (white), IgG2b (dark gray), and IgG3 (light gray) levels after the final immunizations against PvRALP1-Ecto and PvRALP1-Tr were determined by ELISA. (B) Geometric mean concentrations were calculated for each of the four subclasses in each group of three mice and are presented as percentages of the total IgG responses in BALB/c mice. The results are expressed as mean titers ± SD. The p values, calculated using Student’s t-test, indicate the number of sera analysed. Double asterisks, 0.0001 < p < 0.01; triple asterisks, p < 0.0001.